The LADSDeviceStateMachineType state machine represents the Device’s current state. It is inspired by the AnalyserDeviceStateMachineType from the Analyzer Devices Specification.

The LADSDeviceStateMachine is depicted in Figure 15

image019.png

Figure 15 – LADSDeviceStateMachine

The LADSDeviceStateMachineType is formally defined in Table 17.

Table 17 – LADSDeviceStateMachineType Definition

Attribute

Value

BrowseName

LADSDeviceStateMachineType

IsAbstract

False

References

Node Class

BrowseName

DataType

TypeDefinition

Other

Subtype of the FiniteStateMachineType defined in OPC 10000-5

0:HasComponent

Method

GotoOperate

O

0:HasComponent

Method

GotoShutdown

O

0:HasComponent

Method

GotoSleep

O

0:HasComponent

Object

Operate

StateType

0:HasComponent

Object

OperateToShutdown

TransitionType

0:HasComponent

Object

OperateToSleep

TransitionType

0:HasComponent

Object

Initialization

InitialStateType

0:HasComponent

Object

InitializationToOperate

TransitionType

0:HasComponent

Object

Shutdown

StateType

0:HasComponent

Object

Sleep

StateType

0:HasComponent

Object

SleepToOperate

TransitionType

Conformance Units

LADS LADSDeviceStateMachineType

There are four Device states, as follows:

Initialization: The Device is in its initializing sequence and cannot perform any other Task.

Operate: The Device is in Operating mode. The LADS Client uses this mode for normal operation: configuration, control, and data collection.

Sleep: The Device is still powered on and its OPC UA Server is still running, but it is not ready to perform any Tasks until it transitions to the Operate state. This state can be used to represent a PowerSave state where a Device may shut down some of its Components, such as the GUI. It can also be used to represent a Sleep state, where a Device is running with minimal services but ready to be triggered to transition into the Operate state.

Shutdown: The Device is in its power-down sequence and cannot perform any other Task. Optionally, there are devices that can be powered off via physical means, especially simpler ones. The electronics are turned off immediately; therefore, such devices do not transition into a Shutdown state.

Note: Initialization is the state in which the LADS Device waits for the completion of the power-up setup. Its sub-states are out of scope of the LADS specification.

Note: Shutdown is the state in which the LADS Device waits for the completion of the power down sequence. Its sub-states are out of scope of the LADS specification.

Children of the LADSDeviceStateMachineType have additional References, which are defined in Table 18.

Table 18 – LADSDeviceStateMachineType additional References

SourceBrowsePath

Reference Type

Is Forward

TargetBrowsePath

InitializationToOperate

0:FromState

True

Initialization

0:ToState

True

Operate

0:HasEffect

True

TransitionEventType

OperateToSleep

0:FromState

True

Operate

0:ToState

True

Sleep

0:HasCause

True

GotoSleep

0:HasEffect

True

TransitionEventType

SleepToOperate

0:FromState

True

Sleep

0:ToState

True

Operate

0:HasCause

True

GotoOperate

0:HasEffect

True

TransitionEventType

OperateToShutdown

0:FromState

True

Operate

0:ToState

True

Shutdown

0:HasCause

True

GotoShutdown

0:HasEffect

True

TransitionEventType

The Component Variables of the LADSDeviceStateMachineType have additional Attributes, as defined in Table 19.

Table 19 – LADSDeviceStateMachineType Attribute Values for Child Nodes

BrowsePath

Value Attribute

Initialization

0:StateNumber

1

Operate

0:StateNumber

2

Sleep

0:StateNumber

3

Shutdown

0:StateNumber

4

SleepToOperate

0:TransitionNumber

3

OperateToShutdown

0:TransitionNumber

4

OperateToSleep

0:TransitionNumber

2

InitializationToOperate

0:TransitionNumber

1

The GotoOperate Method is used to set the Device into an operating mode. The signature of this Method is specified below. Table 20 specifies its representation in the AddressSpace.

Signature

GotoOperate ()

Table 20 – GotoOperate Method AddressSpace Definition

Attribute

Value

BrowseName

GotoOperate

References

Node Class

BrowseName

DataType

TypeDefinition

ModellingRule

The GotoShutdown Method is used to shut down the Device. The signature of this Method is specified below. Table 21 specifies its representation in the AddressSpace.

Signature

GotoShutdown ()

Table 21 – GotoShutdown Method AddressSpace Definition

Attribute

Value

BrowseName

GotoShutdown

References

Node Class

BrowseName

DataType

TypeDefinition

ModellingRule

The GotoSleep Method is used to set the Device to Sleep. The signature of this Method is specified below. Table 22 specifies its representation in the AddressSpace.

Signature

GotoSleep ()

Table 22 – GotoSleep Method AddressSpace Definition

Attribute

Value

BrowseName

GotoSleep

References

Node Class

BrowseName

DataType

TypeDefinition

ModellingRule